Awww... it will be OK
We had Logan neutered last week... poor little guy. They did his surgery early in the morning and we were told to pick him up after 5... I think we got there at 5:01! Haha! He was groggy and grumpy but he was extra snuggly all night long. We took the pain meds they suggesed (they were NOT very expensive) because his particular surgery was extra invasive (basically he had to be spayed AND neutered because one of his testicles never descended... yeah, I know... TMI!!! LOL) But we only gave him 2 doses and he bounced RIGHT back. By the next morning he was his usual self, getting into mischief with his brother and sisters.
Our vet told us we could feed Logan about 1/2 of what he was used to eating, but not until after we had him home for an hour. But he was NOT interested in food at ALL. He just wanted to curl up on his pillow and sleep! (The next morning, he ate like a GORILLA!!!!!)
We were also told not to bathe him until AFTER we take him back to get the sutures out, 10-14 days post procedure. I'm used to bathing him every 6-7 days, so... he's going to be a dirty boy!!!
Just be calm, because I bet Miss Luma is very tuned in to your emotions. Remember that your vet spays hundreds of animals a year. And... think how much happier your baby will be AFTER it's over! She won't have to go into heat and be miserable and uncomfortable every couple weeks.
I'll send some positive healing vibes Luma's way (and your way, too!)